#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<string.h>
#include<assert.h>
int count(char* a, int len)
{
    assert(a);
    int count = 0;
    char n[127] = { 0 };
    int i = 0;
    int m = 0;
    for (i = 0; i < len; i++)
    {
        int k = strlen(n);
        for (int j = 0; j <=k; j++)
        {
            if (a[i] == n[j])
            {
                break;
            }
            else
            {
                if (j == k)
                {
                    count++;
                    n[m] = a[i];
                    m++;
                }
                continue;
            }
        }
    }
    for (i = 0; i < 127; i++)
    {
        printf("%c", n[i]);
    }
    printf("\n");
    return count;
}
int main()
{
    char a[500] = { 0 };
    scanf("%s", a);
    int len = strlen(a);
    int n = count(a, len);
    printf("%d\n", n);
    return 0;
}